Products (as of 250501)

Completions

Responses is set to replace Completions. Responses combines completions style with Assistants API capabilities in one.

curl https://api.openai.com/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer OPENAI_API_KEY" \
  -d '{
    "model": "gpt-4.1-nano",
    "messages": [
      {
        "role": "developer",
        "content": "You are a helpful assistant."
      },
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }'

Responses

Responses API = Agentic API primitive

• simplistic approach of Completions API with agentic task capabilities.

Built-in tools:

• Web search
• File search
• Computer use

curl https://api.openai.com/v1/responses \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer OPENAI_API_KEY" \
  -d '{
    "model": "gpt-4.1-nano-2025-04-14",
    "input": [
      {"role": "front desk agent", "content": "greet a guest"}
    ]
  }'

Responses vs Assistants API

Responses API will succeed Assistants API after achieving parity.

• Assistants API will sunset around first half of 2026.

Agents SDK

Used to orchestrate single-agent and multi-agent workflows.

• Agents
  • Easily configurable LLMs with clear instructions and built-in tools.
• Handoffs
  • Intelligently transfer control between agents.
• Guardrails
  • Configurable safety checks for input and output validation.
• Tracing & Observability
  • Visualize agent execution traces to debug and optimize performance.

Knowledge Retrieval

Embeddings give total control over chunks, tokens, and history.

• you need to write your own vector store and retrieval logic.

Files API is a black box.

• You don't get the finer control, but it works out of the box.
• Files get deleted after 7 days.